Field of the Invention
The invention relates to a device for placing components of a structure. The invention likewise relates to a method for placing components of a structure. The invention relates particularly to a device and method for placing components of a wind turbine.
Description of Related Art
Although the invention will be elucidated mainly within the context of assembling a high structure such as a wind turbine at sea, the device and method according to the invention can expressly be used both on land (onshore) and at sea (offshore).
The number of high structures erected, maintained or repaired on land or at sea is growing. A typical example is a wind turbine comprising a gondola (or nacelle) which is placed on a mast and forms the housing for electromechanical equipment such as a power generator. The nacelle is also provided with a hub on which a number of rotor blades are arranged. The rotor blades convert the kinetic energy of the wind into a rotating movement of the shaft of the nacelle, which is converted into electrical energy by the power generator.
During the placing of components of such large structures the components are manipulated according to the prior art by a crane placed on a surface, and placed on an already available support structure for the structure. In the case of a wind turbine the support structure can for instance comprise a mast placed on a suitable foundation.
The lifting and placing of large, slender components, in particular wind turbine blades, is hampered by wind load. Wind turbine blades attached to the crane can be exposed here to great and unexpected movements relative to the support structure or relative to already installed components. This makes assembly very much more difficult, or even impossible in the case of strong wind load. A wind turbine blade has to be attached by means of bolt connections to a hub, this requiring a precise positioning of the wind turbine blade relative to a hub already installed on a mast.